Air pressure actuated work holding apparatus



Sept. 4, 1962 J. K. LA TRELL AIR PRESSURE ACTUATED WORK HOLDINGAPPARATUS Filed April 11, 1960 3 Sheets-Sheet 1 INVENTOR.

Arr-02415;.

I 73 jg Sept. 4, 1962 J. K. LA TRELL 3,052,479

AIR PRESSURE ACTUATED WORK HOLDING APPARATUS Filed April 11, 1960 3Sheets-Sheet 2 INV EN TOR.

ATTOPA/EK 5 Sheets-Sheet 3 Q. (11W Arraeuzx Sept. 4, 1962 J. K. LA TRELLAIR PRESSURE ACTUATED WORK HOLDING APPARATUS Filed April 11, 1960 1 H ll llllllll ll mm day v X w mmhl A This invention relates to air pressureactuated vacuum apparatus, particularly as related to work holdingmeans.

It is the primary object of the present invention to provide a novelvacuum pump and related air pressure operated means for releasablyholding work and other objects which heretofore required the use ofmechanically operated chucks and similar clamping devices.

It is another object of this invention to provide novel vacuum operatedwork holding means for use on lathes, drill presses and similarmachines, which may be quickly and easily operated to releasably holdwork in desired positions subject to machining and treatment, in anadvantageous manner not provided for by conventional mechanicallyactuated chucks and similar holding devices.

It is another object of this invention to provide a novel air pressureactuated vacuum pump which will produce and uniformly maintain acomparatively high vacuum in a particularly eflicacious manner in workholding means such as above described or in other means where it isdesired to create subatrnospheric pressure, and wherein at will, thepump may be operated to produce above atmospheric pressure orsubatrnospheric pressure of different values in such holding means orother means.

It is another object hereof to provide a novel work holding member whichis free from mechanical means for engaging and holding the work, theholding action being efiected solely by atmospheric pressure against theexposed surfaces of the work according to the subatmospheric pressureapplied through the holding member against the surface of the workabutting the holding member.

A further object of this invention is the provision in apparatus such asdescribed of novel means for controlling the air pressure which operatesthe Vacuum pump to vary the holding action of the holding member, itbeing possible readily and easily to regulate this action so that thework may be adjusted as desired while being held on the holding memberand as readily immovably held thereon under the holding force providedby the apparatus.

An additional object of this invention is to provide work holdingapparatus such as described which may be rotated at desired speeds whilesecurely holding the work by reason of the particular construction ofthe work holding member and the efficient manner in which the vacuumpump cooperates with the work holding member to uniformly maintain aneffective negative pressure at one side of the work.

A further object of this invention is the provision of a novel workholding member which is in the form of a disk or plate having sealingmeans surrounding one or more openings or depressions in whichsubatmospheric pressures are developed when work bridges the openings ordepressions in engagement with the sealing means, there being valvemeans operable for rendering selected areas of the holding memberoperable and inoperable as desired best to hold in place work of aparticular size or shape.

Yet another object is the provision of a work holding member such asnext above described which may be formed with a series of concentricannular grooves or channels in the work engaging face thereof and isprovided with valved means operable for selectively communicating thegrooves or channels with the vacuum pump for creating the subatmosphericpressures against the work whereby atmospheric pressure is effective tohold the work on the holding member. With this arrangement and thecontrol provisions in the vacuum pump, the latter also may be operatedto direct air at above atmospheric pressure therefrom to the holdingmember and against the work for quickly releasing the work, or theholding action may be regulated as desired to prevent adjustment ormovement of the work or to permit adjusting movement while the work isheld on the holding members.

An additional object of this invention is the provision of a workholding member of the character described which is provided with acentral opening for registration with the bore of the lathe spindlewhereby a part of work may be extended through this opening and into thespindle if this is required, with the holder also operable for holdingother parts of the work thereon upon operation of the vacuum pump.

Other objects and advantages of the invention will be hereinafterdescribed or will become apparent to those skilled in the art, and thenovel features of the invention will be defined in the appended claims.

Referring to the drawings:

FIG. 1 is a fragmentary plan view partly in section of apparatusembodying the present invention shown as applied to a conventionallathe, only portions of which latter are shown;

FIG. 2 is a sectional view on an enlarged scale taken on the line 22 ofFIG. '1;

FIG. 3 is a sectional view on a reduced scale taken on the line 33 ofFIG. 2;

FIG. 4 is a front elevation of a holding member and part of the latheshown in FIG. 1, on a reduced scale;

FIG. 5 is a fragmentary side elevational and part sectional view of amodified arrangement of apparatus of this invention as embodied in alathe; and

FIG. 6 is a sectional View taken on the line 6-6 of FIG. 5 on anenlarged scale.

The illustrative embodiment of the invention as shown in FIGS. 1-4includes vacuum operated apparatus in operative association with aconventional lathe 2, and generally comprising an air jet operatedvacuum pump 3 and related work holding member 4. The pump 3 may bemounted on or adjacent the head stock of the lathe 2, for example, bymeans of a bracket 5 fixed to the head stock. The work holding member 4is mounted on the tubular spindle 6 of the lathe in place of aconventional chuck, there being a hose or conduit 7 for communicatingthe vacuum pump 3 with the work holding member 4. Typical work held onthe member 4 is designated W.

It is to be understood that the apparatus of this invention may beapplied to machines other than here shown, or used in any manner forwork holding or article engaging purposes, since it is contemplated thatthe pump 3 and the Work holding member 4 or any member similar theretowhich is activated by the pump so that air pressure as here providedbecomes the sole medium by which the holding member supports or treatsthe work under control of the pump are within the scope of thisinvention regardless of the manner in which these elements are employedfor work treating or work holding purposes.

The vacuum pump 3 as shown in FIG. 2, is preferably air pressureoperated and generally comprises a sectional body 8 having an inlet 10for air or other gas under pressure, a jet discharge port 11 and portmeans 12 between the inlet port 10 and port 11 which, as will behereinafter described, serves in one operation to produce a vacuum in anannular chamber 13 surrounding the air jet of the pump. A series ofports 14 extending longitudinally in the body 8 communicating thechamber 13 with a chamber 14a having a port 15 to which the hose orconduit 7 is connected so as to lead to the holding member 4 foroperation thereof in response to operation of the pump unit.

Also formed by sections of the body 8 is a chamber 17 into which air orgas is discharged from the discharge port 11 of the pump 3. As hereshown, this chamber 17 has a plurality of exhaust ports 18 open to theatmosphere and covered by means of one or more porous members 19arranged so that the air or gas must pass therethrough to enter theports 18. The members 19 may be composed of any suitable porous materialsuch as felt or the like and should be selected so as to not cause anexcessive back pressure in the chamber 17.

A fitting 20 is connected with the inlet and may be connected with anair or gas pressure supply source, not shown, for supplying air or gasunder pressure to operate the pump. A control valve 21 is mounted in anair line 21' connected to the fitting and is manually operable to varythe flow of air or gas to the pump to control the operation thereof.This valve means makes it possible to vary the value of the negativepressure created by the pump to thereby vary the work holding effect ofthe member 4 as desired.

Another control means is provided for the pump 3 so that at will, it maybe changed from a vacuum pump operation to a means for introducing airor gas under pressure to the holding member 4 to effect release of thework from the holding member. As here shown, this control means includesa normally open valve unit 23 in the pressure chamber 17 operable fromthe exterior of this chamber for closing the jet discharge port 11. Uponrelease of manual pressure on the stem 23' of the valve unit 23, aspring 24 will return the valve member 24' to its normally openposition. When the jet port 11 is closed by the valve member 24', asshown in broken lines in FIG. 2, the air under pressure passes out ofthe pump through the port means 12 into chamber 13, thence through theport 14, chamber 14a, port 15 and conduit 16 to the work holding member4 to apply a positive pressure and nullify the holding action ofatmospheric pressure on the work and thereby release the work from themember 4. When the valve unit 23 is released and moves to open the port11, the pump operates to develop a vacuum. With this arrangement it isnot necessary to shut off the flow of air to the pump in order torelease the work from the holder 4.

More specifically, the pump unit 3 preferably includes a body section 25which is cylindrical and has its inner end 25 bored to receive an end ofanother cylindrical body section 26 which latter is held in place by anannular body section 27 threadedly engaged as at 28 with the inner end25 of the body section 25, there being a flange 27' on the annularsection 27 overlying a flange 26' on the section 26. The flange 26'overlies the inner end portion 25 of the section 25, there being asealing ring 28 between the flange 26 and the end portion 25 to form aseal for the aforementioned annular chamber 13 which, it will now beobserved, is advantageously formed between the opposed portions of thebody sections 25 and 26.

The pressure chamber 17 is formed by a cylindrical shell 29 which at itsinner end is threaded on or otherwise suitably secured to the annularbody section 27. A flanged cap member 30 is threaded into the outer endof the shell 29 and supports the valve unit 23.

The normally open valve unit 23 has its stem 23 slidable through anopening 31 in the cap 30, there being a spring keeper 32 on the stem 23to engage with a boss 33 on the cap to limit outward movement of thestem. The spring 24 is confined between this keeper and an annulargroove 26a in the outer end of the body section 26 so as to hold thevalve member 25 away from the jet discharge port 11.

The annular porous members 19 are preferably formed of felt or othersuitable material and are frictionally retained in an annular space 35formed between the reduced outer end of the body section 26 and the wallof the cylindrical shell 29. The innermost of the members 19 engages theannular body member 27 and flange 27 and covers the circular series ofexhaust ports -18 formed in the body section 27.

The inlet 10 is provided in the body section 25 so as to open on oneside thereof, the inner end of the inlet also opening into an axial bore36 in this body section 25. The bore 36 is closed by a Wall 37 at theouter end of the body section and the other end of the bore 36 isthreaded.

A jet nozzle member 38 threadedly engages in the bore 36 which iscounterbored to form a shoulder 39 on which rests a flange 40 of thenozzle 38. The nozzle 38 has a through passage 41 extending axiallythereof, this passage having a flared intake end 41a and a reducedthroat 41b to create the desired venturi action or suction at the port12 due to increased air velocity and reduced pressure in the venturithroat 41b. The venturi passage expands as indicated by the flaringpassage 55 extending through an exhaust tube 56 which is disposed in thebore 43 of body section 26, retained in place by set screw 57 or othersuitable means, and sealed as by an O-ring 56a. Preferably, in order tomaintain turbulence at a minimum with consequent constancy of thesuction effect, the discharge end of the venturi throat 41b is the samediameter as the inlet to flaring passage 55.

The inner end of exhaust tube 56 is concave as at 58, and is spaced fromthe conical end 42 of nozzle 38 to define the annular port 12, and theport 12 may be varied or adjusted by axial adjustment of exhaust tube 56upon loosening of set screw 57.

The inner end of an axial bore 43 through the body section 26 receivesthe inner conical end 42 of the nozzle 33 so as to define an annularpassage or port 44 between the opposed cylindrical surfaces of thenozzle and the wall of the bore 43, this passage leading into theannular chamber 13.

The inner end of the body section 26 is formed with a concave face 46bordered by a cylindrical edge portion 47. The face 46 is opposed to andspaced outwardly from the body section 25 to form the annular chamber13, there being a felt or similar porous screen member 48 of annularform confined between the adjacent end of the body section 25 and thecylindrical edge portion 47 of the body section 26. The screen member 48is interposed between the circular series of ports 14 in the bodysection 26 and the chamber 13. The port 15 is provided in a closureplate 50 held by screw fastenings 51 against the body section 26 whichlatter has a recess therein forming the chamber 14a from which lead theports 14 and the port 15, there being a felt or other type screen disk53 in the chamber 140 for covering the ports 14 to exclude dust andsimilar foreign matter from entering the pump unit.

The *work holding member 4 as here shown, comprises a disk-like body 60having a tubular hub 61 adapted to be threaded onto the lathe spindle 6in the manner of a conventional chuck. A central opening 62 in the body60 is aligned with the bore 62a of the hub 61 and the bore of spindle 6so that portions of the work held on the body 60 may be disposed inthese bores.

The work engaging face of the disk-like body 60 of the holding member 4is provided with a series of concentric grooves 64 and ribs 65, the ribshaving small grooves 66 therein for reception of sealing rings 67. Thesesealing rings are disposed to form seals with the work when the latteris placed against the member 4 so that the grooves 64 will form annularchambers in which subatmospheric pressures are produced.

The back of the disk-like body 60 of the member 4 is provided with anannular chamber 68 closed by a back plate 69 and sealed by sealing rings69'. The plate 69 is secured within a recess 70 in the body 60 by meansof fastenings 71. Ports 72 in the body 60 communicate the chamber 63with the grooves 64, there being a tubular valve member 73 axially screwthreadedly adjustable in each port 72 between positions opening andclosing the ports. Each valve 73 is adapted to seat against acompressible seat 74 countersunk in the back plate 69, the bore 73through the valve being closed when the valve is seated and opened whenthe valve is unseated. A slot 75 for reception of a screw driver isprovided in the outer end of each valve member 73 to facilitate openingand closing adjustment thereof.

Means are provided for operatively connecting the conduit 7 with thework holding member 4 so that the vacuum pump 3 is in directcommunication with the chamber 68 in the back of the member 4 at alltimes and is subject to communication with the concentric grooves 64when the valves 73 are unseated. As here shown, this means comprises anannular member 77 surrounding the hub 61 of the member 4 and providedwith an inlet port 78 which communicates with a continuous groove 79extending circumferentially on the exterior of the hub. The groove 79communicates with the chamber 68 through a port 80 formed in the hub.One end of the conduit 7 leading from the pump 3, as here shown, isscrewed into the inlet port 78 in the annular member 77 therebycommunicating the pump with holding member 4.

Any suitable means may be provided to mount the annular member 77 towhich the conduit 7 is connected on the hub 61 so that the hub 61 andwork holding member 4 may rotate freely relative to the member 77. Ashere shown, a nut 83 is axially adjustable on the exterior of the hub 61and confines the annular member 77 between it and the back plate 69 insuch a manner that the member 4 and hub 61 thereof may rotate freelyrelative to the member 77. A set screw 83 holds the nut 83 againstmovement out of adjusted position. Sealing rings 84, 85 and 86 arearranged to form fluid tight seals around the member 77. A lubricantinlet fitting 88 may be provided on the member 77 for introducing alubricant in channel 89 and lubricant passages 90 formed in the member77, whereby free rotation of the holding member 4 relative to theannular member 77 will be assured without undue friction and consequentwear.

As shown in FIG. 1, work designated W in the form of a circularrelatively thick member may be securely held on the work engaging faceof the work holding member 4 as a result of the negative pressure actingagainst the inner face of the work and the atmospheric pressure againstthe exposed faces of the work. It has been found that work of this typeor any other type which has a surface adapted to form a seal around thedepressions or grooves 64 in the work holding member, when engaged withthe sealing rings 67 on the latter, will be securely held, it beingpossible to rotate the spindle and work at any desired speed while thework is securely and immovably held on the work holding member.

It is important to note that by reason of the flow reversal valve 23 inthe pump 3, the operator may depress the stem 23 of the valve andthereby cause air under pressure that has entered the pump to be forcedagainst the face of the work opposite the depressions or grooves in themember 4, whereby the work may be quickly released for removal from thework holding member. An advantage of this is that it is not necessary toshut ofi? the flow of actuating air to the pump in order to release thework from the holding member 4.

Another advantage of the apparatus of this invention is that should itbecome necessary to adjust the work on the work holding member while theWork is held thereon, this readily may be etfected by manipulating thevalve 21 for reducing the flow of actuating air to the pump and therebymodifying the vacuum so that atmospheric pressure will exert sufficientforce to hold the work on the work holding member, yet permit ofadjustment of the work relative thereto.

FIG. illustrates a modified form of the invention wherein an air jetoperated vacuum pump 92 identical with the vacuum pump 3 shown in FIGS.l4 and a work holding member 93 of substantially the same constructionas the previously described work holder 4, are embodied in aconventional lathe 94 so that the conduit 95 communicating the pump withthe work holding member is extended through the hollow spindle 96 of thelathe. With this arrangement the pump 92 is disposed adjacent one end ofthe spindle 96, whereas the work holding member 93 is mounted on theother end of the spindle. The pump 92 as here shown, is supported on theprojecting end of the conduit 96. The conduit 95 is movable axially inthe spindle 96 while connected to the pump and the work holding member,such movement being effected in the operation of detaching the holdingmember as will be hereinafter described.

Air under pressure from a source not shown is supplied to the pump 92through an intake pipe 97 in which a manually operable valve 98 isoperable to control the flow of air into the pump in the same manner asthe control valve 21 in the previously described form of the invention.A normally open flow-reversing valve 99 identical with the valve 23 isprovided in the pump 92 and is accessible for operation at one end ofthe pump.

The Work holding member 93 as here shown, comprises a disk-like body 190of circular form having a threaded hub 101 adapted to be screwed ontothe lathe spindle 96 in the manner of a conventional chuck. The workengaging face of the member 93 is substantially the same as in thepreviously described work holding member 4 in that it is provided with aseries of concentric grooves 162 and ribs 103, the ribs being providedwith sealing rings 104 to engage the work so as to form seals againstthe work and around the respective grooves.

Ports 105 extend from a chamber 106 in the back of the holding member 93into the grooves 103, each port being provided with a tubular valve 107threadedly axially adjustable therein between positions for opening andclosing the bore therethrough. A seat 108 is provided in the chamber 166for each valve 107. The arrangement of the valves 107 makes it possibleto render diiferent portions of the work holding face of the member 93operable and inoperable for creating dilferential pressures against thework.

Means are provided to connect the conduit 95 with the chamber 106 in thework holding member 93 so that the latter may rotate with the spindle 96relative to the conduit while maintaining a fluid tight joint of theconduit with the work holding member. As best shown in FIG. 6, thismeans comprises a quick action coupling 109 consisting of a nipple 109on the conduit 95 and a socket 110 on the back of the work holdingmember 93, the socket communicating with the chamber 106 through atubular fitting 110 threadedly connected to the work holder and thesocket 110. A latching sleeve 111 is mounted on the socket 110 so as tobe biased by a spring 112 to a position for holding bearing balls 113 inengagement with an annular groove 114 in the nipple. The bearing balls113 are radially movable in the openings 115, the diameter of theseopenings permitting the balls to protrude inwardly for engagement in thegroove 114 in the nipple without allowing the balls to drop through theopenings. When it is desired to disconnect the conduit 95 the hub 101 ofthe holding member 93 is unscrewed from the spindle 96, the socket unit119 and sleeve 111 turning with the holding member during the unscrewingoperation. As the hub is being unscrewed the conduit 95 is moved axiallyin the spindle, and when the hub is free of the spindle, access to thecoupling 109 may be had by pulling outwardly on the member 91 to slidethe conduit 95 out of the spindle sufficiently to reach the coupling.The latching sleeve 111 may now be retracted against the action of thespring 112 so that an annular rib 116 in the sleeve is disposed out ofengagement with the bearing balls 113 thereby permitting the socket tobe removed from the nipple. A snap ring 117 on the socket limits theoutward movement of the latch sleeve to a position locking the bearingballs in place in the nipple groove 114. The outer end of the nippleabuts a compressible sealing member 118 within the nipple so as toprovide a leakproof joint.

When the spindle and Work holding member 93 are rotated, the socket 110with the latch sleeve 111 and bearing balls 113 thereon are rotatedfreely around the nipple, the bearing balls acting as anti-frictionmembers. It should be noted that the portion of the conduit 95 enteringthe rear end of the spindle 96 is slidable in a tubular member 120inserted into the spindle for rotation therewith, there being a ballbearing unit 121 in the enlarged outer end 122 of this tubular member120 to permit the tubular member and spindle to rotate freely around theconduit 95, also permits free axial movement of the conduit 95 in thespindle. A clean-out opening 123 is provided in the work holding member93 to afford access to the chamber 106 and related parts, there being aplug 124 having a sealing ring 125 thereon removably positioned in andclosing this clean-out opening.

While specific structural details have been shown and described, itshould be understood that changes and alterations may be resorted towithout departing from the spirit of the invention as defined in theappended claims.

I claim:

1. Air pressure actuated apparatus comprising: an air pump; air pressureapplying means for applying subatmospheric pressure and aboveatmospheric pressure to means for holding and releasing work accordingto said pressures; conduit means connecting said pump with said airpressure .applying means; and flow control means embodied in said pumpmanually operable for controlling the direction of flow of air passingthrough the pump optionally to create subatmospheric pressure and aboveatmospheric pressure in said conduit means and said air pressureapplying means.

2. Air pressure actuated apparatus comprising: an air pressure operatedvacuum pump; air pressure applying means for applying subatmosphericpressures and above atmospheric pressures to means operable to hold andrelease work according to said pressures; conduit means connecting saidvacuum pump with said air pressure applying means; valved intake meansfor said pump operable to control the flow of air under pressure intosaid pump; and flow control means embodied in said pump manuallyoperable for controlling the direction of flow of air passing throughthe pump optionally to operate the pump for creating subatmosphericpressure and above atmospheric pressure in said conduit means and saidair pressure applying means.

3. Air pressure actuated apparatus comprising: an air pressure operatedvacuum pump; air pressure applying means; conduit means connecting saidvacuum pump with said air pressure applying means; valved intake meansfor said pump operable to control the flow of air under pressure intosaid pump; flow control means embodied in said pump manually operablefor controlling the direction of flow of air passing through the pumpfrom said valved intake means optionally to operate the pump forcreating subatmospheric pressure and above atmospheric pressure in saidconduit means and said air pressure applying means; and means forconnecting said air pressure applying means to a structure in which itis desired to apply said pressures.

4. Air pressure actuated apparatus comprising: .an air pressure operatedvacuum pump; air pressure applying means having an outlet through whichsubatmospheric pressure and above atmospheric pressure may be applied tomeans which will operate in response to said pressures; conduit meansconnecting said vacuum pump with said air pressure applying means;valved intake means for said pump operable to control the flow of airunder pressure into said pump; and flow control means embodied in saidpump manually operable for controlling the direction of flow of airpassing through the pump from said valved intake means optionally toactuate said pump for creating subatmospheric pressure and aboveatmospheric pressure in said conduit means and through said outlet ofsaid air pressure applying means.

5. Air pressure actuated vacuum apparatus comprising: a body havinginlet means adapted for connection with a source of air under pressure;means in said body providing a jet pump through which air under pressureis passed from said inlet means; means in said body providing a vacuumchamber surrounding said jet pump; said jet pump having a vacuum port incommunication with said chamber; said jet pump having a discharge port;means in said body providing an exhaust chamber into which air isdischarged from said discharge port; said body having exhaust ports forventing air from said exhaust chamber; means in said body providing aport which opens exteriorly of the body for connection with means forapplying pressure developed by the pump; and passage means in said bodycommunicating said vacuum chamber with said last named port.

6. Air pressure actuated vacuum apparatus comprising: a body havinginlet means adapted for connection with a source of air under pressure;means in said body providing a jet pump through which air under pressureis passed from said inlet means; means in said body providing a vacuumchamber surrounding said jet pump; said jet pump having a vacuum port incommunication With said chamber; said jet pump having a discharge port;means in said body providing an exhaust chamber into which air isdischarged from said discharge port; said body having exhaust ports forventing air from said exhaust chamber; means in said body providing aport which opens exteriorly of the body for connection with means forapplying pressure developed by the pump; passage means in said bodycommunicating said vacuum chamber with said last named port; and porousmeans in said exhaust chamber disposed across said exhaust ports.

7. Air pressure actuated vacuum apparatus comprising: a body havinginlet means adapted for connection With a source of air under pressure;means in said body providing a jet pump through which air under pressureis passed from said inlet means; means in said body providing a vacuumchamber surrounding said jet pump; said jet pump having a vacuum port incommunication with said chamber; said vacuum port being uninterruptedcircumferential-ly of said jet pump; said jet pump having a dischargeport; means in said body providing an exhaust chamber into which air isdischarged from said discharge port; said body having exhaust ports forventing air from said exhaust chamber; means in said body providing aport which opens exteriorly of the body for connection With means forapplying air pressure developed by the pump; and passage means in saidbody communicating said vacuum chamber with said last named port.

8. Air pressure actuated vacuum apparatus comprising: a body havinginlet means adapted to be connected With a source of air under pressure;means in said body providing a jet nozzle in communication with said1nlet; an exhaust tube mounted in said body in alignment with said jetnozzle and in axially spaced relation thereto to form a vacuum port thatis uninterrupted c rcumferentially of the outlet of .said jet nozzle;means in said body providing a vacuum chamber surrounding said et nozzleand in communication with said vacuum port; and means in said bodyproviding a port leading from said vacuum chamber and which opensexteriorly of the body.

9. Air pressure actuated vacuum apparatus comprising: 'a body havinginlet means adapted to be connected with a source of air under pressure;means in said body providing a jet nozzle in communication with saidinlet; an exhaust tube mounted in said body in alignment with said jetnozzle and in axially spaced relation thereto to form a vacuum port openthroughout 360 around the outlet of the jet; means in said bodyproviding a vacuum chamber surrounding said jet nozzle and incommunication with said vacuum port; means in said body providing apassage leading from said vacuum chamber and which opens exteriorly ofthe body; and valve means operable to close said exhaust tube wherebyair under positive pressure will be directed through said vacuum pont,said vacuum chamber and said passage.

-10. Air pressure operated apparatus comprising: a body having inletmeans LfOI' connection with a source of air under pressure; means insaid body providing a jet nozzle in communication with said inlet means;means connected with said body providing an exhaust chamber having anexhaust port which opens to the atmosphere; means in said body providingan exhaust passage for receiving air from said nozzle and dischargingthe air into said exhaust chamber; means providing a vacuum chambersurrounding said nozzle; said passage forming means being spaced fromsaid nozzle to define around said nozzle a vacuum port which opens intosaid vacuum chamber; means in said chamber providing a vacum passageleading from said vacuum chamber and which opens exteriorly of saidbody; and valve means in said exhaust chamber operable for closing saidexhaust passage whereby air under pressure directed from said nozzlewill pass through said vacuum port, said vacuum chamber and said vacuumpassage.

'11. Air pressure operated apparatus comprising: a body having inletmeans for connection with a source of air under pressure; means in saidbody providing a jet nozzle in communication with said inlet means;means connected with said body providing an exhaust chamber having anexhaust port which opens to the atmosphere; means in said body providingan exhaust passage for receiving air from said nozzle and dischargingthe air into said exhaust chamber; means providing a vacuum chambersurrounding said nozzle; said passage forming means being spaced fromsaid nozzle to define between said passage forming means and said nozzlea vacuum port which opens into said vacuum chamber; means in saidchamber providing a vacuum passage leading from said vacuum chamber andwhich opens exteriorly of said body; valve means in said exhaust chamberoperable for closing said exhaust passage whereby air under pressuredirected from said nozzle will pass through said vacuum port, saidvacuum chamber and said vacuum passage; spring means biasing said valveto open said exhaust passage; and means operable on the exterior of saidexhaust chamber for moving said valve to close said exhaust passage.

12. Air pressure operated apparatus comprising: a body having inletmeans for connection with a source of air under pressure; means in saidbody providing a jet nozzle in communication with said inlet means;means connected with said body providing an exhaust chamber having anexhaust port which opens to the atmosphere; means in said body providingan exhaust passage for receiving air from said nozzle and dischargingthe air into said exhaust chamber; means providing a vacuum chambersurrounding said nozzle; said passage forming means being spaced fromsaid nozzle to define between said passage forming means and said nozzlea vacuum port which opens into said vacuum chamber; means in saidchamber providing a vacuum passage leading from said vacuum chamber andWhich opens exteriorly of said body; valve means movable into a positionfor opening said exhaust passage as well as into a position for closingsaid exhaust passage; means biasing said valve means to occupy one ofsaid positions; and means operable from the exterior of said exhaustchamber for moving said valve means into the other of said positions;said valve means when in said position for closing said exhaust passagecausing air under pressure to be passed out through said vacuum port,said vacuum chamber and said vacuum passage.

References Cited in the file of this patent UNITED STATES PATENTS1,842,500 Beede Jan. 26, 1932 2,043,027 Beede June 2, 1936 2,457,388Lung Dec. 28, 1948 2,644,274 Bailey July 7, 1953 2,730,370 Brewster Jan.10, 1956 2,852,264 Granata Sept. 16, 1958

